When Ebola first arrived in Europe on Sept. 29, 1976, the vials of the virus were carried from Zaire, now the Democratic Republic of the Congo, in a shiny blue thermos on a passenger flight.

Three lab workers in Antwerp, Belgium, received the thermos and prepared to open it on a lab bench. The precautions they took and the room they were in were appropriate for handling organisms like salmonella or tuberculosis, with none of the security procedures or body suits that we now associate with manipulating Biosafety Level 4 pathogens like Ebola.

All the lab team knew was that it was receiving blood samples from an unusual epidemic that was suspected to possibly be some form of "yellow fever with hemorrhagic manifestations," according to Peter Piot, one of the three in the room and a co-discoverer of the Ebola virus. Piot wrote about the experience in his book "No Time to Lose: A Life in Pursuit of Deadly Viruses."

Wearing latex gloves and no other protection, they opened the cheap plastic thermos that was supposed to hold two glass vials of blood that had been drawn from a Flemish nun who was too sick to be evacuated from the Congo.

One of the vials was broken — the thermos hadn't been stored carefully enough on the passenger plane that carried it from Kinshasa.

Blood and broken glass mixed with half-melted ice. Piot, who was a 27-year-old medical school graduate and junior lab worker at the time, describes that moment:

We didn't even imagine the risk we were taking. Indeed, shipping those blood samples in a simple thermos, without any kind of precaution, was an incredibly perilous act. Maybe the world was a simpler, more innocent place in those days, or maybe it was just a lot more reckless.

If the team had any idea what Ebola was at the time, the virus would have been shipped to one of the three non-Soviet labs that were considered able to handle hemorrhagic viruses.

But because the team had no idea of exactly what it had received, Piot's two coworkers, postdoc student René Delgadillo and Guido Van Der Groen, reached into the soupy viral mess and picked out the intact vial.

"It makes me wince just to think of it," Piot writes.

To isolate the virus, the three — still maskless and with no protection but gloves — injected the blood into cell cultures and into the brains of adult and baby mice ("I never liked this aspect of the work," Piot writes).

They tested the blood, cell cultures, and mice over the next several days for known hemorrhagic diseases like yellow fever and Lassa fever, but antibodies for those diseases never turned up. Their boss, Stefaan Pattyn, looked into the outbreak at the time and found a village called Yambuku that seemed to be the origin.

The Flemish nun had died on Sept. 30, and pieces of her liver were flown to Belgium on yet another passenger flight.

Pattyn thought the virus must be a new rare hemorrhagic fever, a disease that causes the seemingly constant bleeding that accompanies some Ebola cases, and the sort of fever that the lab was not certified as safely equipped to handle — but they wanted to keep investigating anyway.

Piot says that at this point, he was "inflamed" with interest and "loved the detective thrill." His medical school adviser had told him to stay away from infectious diseases because they had "all been solved."

This one had not been solved, though, and it seemed like the chance to both discover something new and to save lives.

Piot still did not know how incredibly deadly the virus was — that it was a hemorrhagic fever was strongly suspected but still not confirmed — but all evidence pointed to something grave. The World Health Organization ordered the samples shipped to one of the only labs equipped for hemorrhagic viruses, Porton Down in Britain, and from there they were sent to the CDC in Atlanta, considered the reference library for these types of diseases.

But Pattyn kept a few samples. "By this point for him to keep us working on these samples was sheer folly," Piot writes. "He knew we were not equipped to do the work in safety."

Piot doesn't know why exactly — perhaps Pattyn was reluctant to send away what his team had been first to examine. "It was new, it was exciting — just too exciting to hand it over to the Brits or, in particular, to the Americans," he writes. They kept a few cell cultures and some newly infected mice, Pattyn saying they needed a few more days before they were ready for transport. And they kept examining them to see what they could find.

Before long, something went wrong. Pattyn, who was in charge but was a little clumsy in the lab, Piot said, dropped an Ebola vial on the floor, where it shattered onto Delgadillo's shoes.

"Godverdomme," or goddamn, Pattyn said. They disinfected the floor and removed the shoes.

Only then did Piot realize how dangerous their behavior might have been and the risks they were taking.

After the cells they had kept were ready for analysis, the lab technicians took a sample and took pictures with an electron microscope. The virus was huge. Piot said they saw "very large, long, wormlike structures: nothing like yellow fever."

Pattyn realized that it looked like the longest known virus in existence, a rare lethal hemorrhagic fever called Marburg that had killed a number of lab workers in Germany nine years before, after they had handled infected monkeys.

They finally realized their folly and sent the rest of the samples to the high-security CDC labs. If the virus were Marburg or something related, they knew that they lacked the equipment to study it.

And they started looking for money to go to Zaire and see the outbreak for themselves.

Confirmation soon arrived from the CDC that the virus was not Marburg; it was something new. This was the first time the world recognized the virus that came to be known and feared as Ebola. That 1976 Zaire outbreak gave the virus its name, and it killed 88% of those infected, 280 people — the most of any outbreak until the current one.